There were many of you fine hams who emailed me to comment on my
previous post. To avoid spending all day answering your messages I'm
replying here... and a big THANKS for your help.
As it turns out those of you who mentioned feed line length were
correct. Amazing..... I have read about this phenom but never
experienced it until now. While the antenna SWR on 15 meters at 21.030
(<1.5 @ 21.320) is about 2:1 the addition of abt 3 feet of coax makes
the meters in both the WM-1 and Bird 43 read 100 watts output into the
line although the indicated SWR does not change. When I put either
meter inline without the 3 foot section of coax they both read 70 watts
out....... so the answer was the feedline length....... who would think
that <3 feet would make a difference. The actual output of the rig
remains at 100 watts or so. Boy ! What a good theory lesson ! Sure is
a surprise when things you remember reading about suddenly become
apparent. I had a local ham tell me that years ago he had to use an
additional 15 feet of coax to get full output from his Collins 30-S1
amp. Bet those "old" hams who remember when feedline length/matching
was more critical to most systems are grinning right now.
73
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Michael Melland, KB9QHU
Winneconne, Wisconsin, USA
FISTS #4387, 10-10 #69281, QRP-L #1656
CW, SSB, and Electronics
List Administrator: grundig@qth.net
http://www.vbe.com/~badgerhttp://www.qsl.net/kb9qhu
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